At your distance, most any set top antenna should work well. The Silver Sensor is a good antenna for your current channel lineup, as it appears that all their digital signals are on UHF. The best place to get information about your local channel selection is
TVfool.com. You can input your address and it will show the direction and approximate signal strength for each station in your area.
You can also see what your channel lineup will look like after Feb. 2009, since some channels will be changing frequencies. According to your post 2/2009 plot, it looks like WPVI-DT(ABC) will be switching to low VHF channel 6 and WHYY-DT(PBS) will be switching to high VHF channel 12. At your distance, there's a good chance the Silver Sensor could pick up digital channel 12, but I wouldn't count on it getting channel 6. As a rule, the lower the channel frequency, the larger the antenna you will need to get it. When you see the large all-channel antennas on people's roofs, the longest elements in the back are meant to pick up the lowest VHF frequencies, such as 2-3.
Anyway, in your instance you will want an antenna that at least has a shot at low VHF reception, and that will mean rabbit ears. If I were to recommend an indoor antenna for your location, I would suggest the Terk HDTVi. It's UHF reception is similar to the Silver Sensor, but it also has a pair of rabbit ears for VHF reception. Don't get the HDTVa, as this is the amplified version, and as close as you are to the transmitters you are likely to overpower your digital signal, which is just as bad as getting too little signal.
Every home's reception is different depending on certain factors, so it's a good idea to go cheap at first (for indoor antennas) just in case your first choice doesn't work so well. Most stores like Best Buy seriously over charge for the HDTVi, so I find the best place to get one is Ebay. It's pretty common to find one for $20-25, which is not bad.
Have you tried any indoor antennas yet? If not (before you spend for an antenna on Ebay), grab any cheap, unamplified rabbit ear set top antenna from Walmart or Target and see what kind of reception you get. The great thing about this is you can return the antenna for a refund if it doesn't do the job for you.
Hope this helps a bit. Good luck in your OTA reception hunt.