To answer the original question, Yes. You can use 609/906 on toms. They are a bit more flexible in that you can use them for gtr cabs too, and if you are short on stands they will hang on the gtr cab readily saving you more money and stage space.
I am not too picky about tom mics. I'll be perfectly happy with 57's or whatever you have. You can make anything work if you know what you are doing. Like some previous poster said, many bands for years used extra sm58's on toms and it worked fine.
Truthfully, if budget is the biggest concern, the CAD drum mic kit (the bigger one, not the cheapest one) is actually pretty dang decent for the 100 bucks you'll pay on the used market. The kick mic is I'll dare say, actually pretty good. It also excels on floor toms. Although it would be hard to position on a kit with a low ride cymbal over the floor tom.
http://cgi.ebay.com/CAD-Six-Piece-Drum-Microphone-Set-6-PC-M ic-Kit-w-Case_W0QQitemZ230431978046QQcmdZViewItemQQptZLH_Def aultDomain_0?hash=item35a6d0f23e#ht_3120wt_1167
This is the kit I'm talking about. You'll find these on Craigslist for a C note all day.