I use a Ryobi scroll saw for mine. Bit I would suggest maybe a delta or dremel scroll saw for the following reason: The ryobi uses a "T" rod across the top of the blade to hold it in. This is great because you dont need any tools to change blades and it is fast, but the downside is you cannot find any of the round blades for it. The Ryobi comes with set screws for these type of blades since they dont have the "T" bar across the top of them but the set screw doesnt hold well and those round blades come in very handy. As for a band saw I have not found anything I need a band saw for yet. the scroll saw can cut up to 2" thick wood and if you need to cut anything thicker than that you can do that bit by hand.
Second useful too is the micro table saw you can get them at places like micromark tools which is on the web i dont have the url at the moment. The next tool I would have would be a nice sized Drill press as it is very handy for drilling pervect verticle holes and good for drilling lightening holes.
those are about all the main tools you will need anything else like a lathe router etc is just nice to have but seldom used. that is also assuming you have the standard model building tools ie exacto, razor plane, dremel clamps etc. Personally all I have is the scroll saw and a hand drill, and a dremel drill press stand for my dremel tool. But my father has a complete wood shop so ocassionally I go over to his place and use his table saw and drill press which gives me a reason to go pester him.
Get a scroll saw and as you cut more and more kits you will come across things you would like to get to make things easier but a good saw and hand drill will cover almost anything you would want to do. I been going more and more with laser cut kits from Lazer-works
http://www.lazer-works.com/ as it is almost as cheap as me buying the wood and cutting it myself example the Ziroli Stuka I can get a laser cut short kit for $125 that is as much as me buying the wood and taking the time to cut it but I get a perfect laser cut shortkit for the same price as me doing it.
Joe