I had 1 great delivery with Ebuyer and the prices were great and everything worked, other experiences weren't so pleasant and there was a LOT of problems simply signing up. The online ordering system is awful esp the stock count, the mathematics they employ are inaccurate and I've heard far too many horror stories from too many trusted sources and this all coupled with my own experience means I'd never consider Ebuyer no matter if their prices were 10 times cheaper than the rest. I don't warn people away lightly and I'm sure there are many satisfied Ebuyer customers but my advice is to use one of the other sites I listed and I can certainly vouch for Dabs, Komplett and Watford Savastore.
The Rad8500LE is simply clocked lower and the perf diff is about 10%, other than the clock speed they are identical. Clocks should be 8500=275/275 8500LE=250/250 however the Rad8500 series of cards have always had a HUGE variance in clock speeds and even some of the functionality like dual RAMDACs for dual display were quietly omitted. So you could find an 8500=230/200 or 275/275 both sold under the same name, make 100% certain of the clock speeds (230/230 is okay but 250/250 is the least you really want) and if you want dual display make 100% sure it has dual RAMDACs even if it has the ports. Another thing to note is that the 128MB versions of the 8500 series are faster meaning a Rad8500LE-128MB is a better idea than a Rad8500-64MB. The GF4TI4200 show the same speed boost from 128MB even when a game doesn't use more than 64MB BUT 4200-128MB use different clock speeds to the 4200-64MB and 4200-8X-128MB which make the 4200-64MB and 4200-128MB equally good. The GF3 cards don't show the same boost so the 128MB version is only worth it for 'future proofing', a boost in the few games liking more than 64MB and for ease of selling on at a later date.
The GF3TI200 is a fair bit slower than the Rad8500LE while the GF3TI500 tends to be a tad faster than the Rad8500LE. HOWEVER much like the GF4TI4200 the GF3TI200 is intentionally underclocked and nearly all have a LOT of extra clock speed in them, this meant the TI200 would usually beat the Rad8500LE once o/c'ed, of course the 8500LE o/c's too but not as much. But there's more, the GF3 cards were designed with 3D in mind and outside of gaming the GF3 cards fall down in several places when you compare them to the Rad8500 series ... image quality, TVout, DVD playback and dual display are all key areas where the Radeons are MUCH better than any GF3, and that's one reason for the GF4 series which addressed all of these issues and added a speed boost too!
Of course there is now the Rad9000 series which is intended to do battle with the GF4MX series, little more than suped up GF2 technology and VERY much inferior to the GF3 when it comes to gaming. As such the Rad9000 series is a LOT better than the GF4MX cards but still worse than the Rad8500 series which is deemed to be renamed Rad9100. The Rad9000PRO is significantly faster than the Rad9000, both are still good cards but a GF3TI200 is faster (though they still have their downsides). Hope that helps to clear up the confusing array of gfx cards out there a little bit.
You don't need PC3200 with any AthlonXP. For all AthlonXP running with 133/266FSB PC2100 is more than sufficient although given the price diff it makes sense to plump for PC2700 not only for better future-proofing but to allow 266+333 (FSB+RAM) operation or 266+266 operation with lightning RAM timings. Obviously for 333FSB usage you need PC2700, and that goes for o/c'ing a 266FSB AthlonXP for which the XP2400+ is VERY nice for (as soon as prices decrease). I'd say save your cash unless you get PC3200 at a bargain price! Dual DDR on nForce2 doesn't give a huge boost and it is of most benefit if you use the onboard GF4MX gfx, there is a gain but you won't miss it if you use 1 stick and wait for DDR prices to drop (and your pockets to refill). You could add 2x256MB now leaving 1 empty slot for future expansion and there should be no problem at all adding another 512MB stick as the DIMMs don't have to match at all.
See how the prices are and what's new at the time you're looking to buy, even the end of January could make things look very different! Until then XP2400+, 512MB PC2700 - 3200 and GF4TI - Rad9700 seem like fine things to have in mind.