I bought a clamp-on straight edge similar to this a while back. It works great for both my saw and router. It's only downfall is that it will slide if you put too much pressure on it. I think I got mine for around $30 at Menards.
https://www.amazon.com/E-Emerson-Tool-C50-Contractor/dp/B003TXSAHU
I think that a cutting guide like http://www.amazon.com/E-Emerson-Tool-C50-Contractor/dp/B003TXSAHU is better than that one; you can cut at whatever width you like, rather than being limited to a 24" width. And honestly, it's not hard to cut a length of plywood and simply use that as your cutting guide.
This, a million times this, to everything that was just said.
The Junior is much better than the mini, and when you factor in the cost of starter screws and a long-robertson, it's about the same cost as the mini-kit.
With regard to the table-saw, go into the big-box and play with all of the demos until you find one with a fence that stays parallel with the blade every time. Unlock the fence, move it around, push on the far end so it's out of square, and then lock it down; does the end you pushed on snap over into square?
If you can't find a tablesaw in your price range with a decent fence, just give up on it; a tablesaw with a bad fence is more work than a circular saw. Buy a straight-edge guide and just use the circular saw.
Do definitely look at used table-saws though.
Oh, and buy clamps! At the very least you're going to need a small easy-to-use-but-powerful clamp to clamp the Kreg to the work, either a huge spring clamp, the vise-grip-style clamps like Kreg sells, or a barclamp/F-clamp are probably needed here. You'll probably want some collection of clamps to hold your work together while you screw-in the pocket screws too, if your mostly building right angles, the Kreg pocket-hole clamp is actually pretty good, otherwise you'll need one or two very long F clamps, quick-grip clamps, or pipe clamps.
If you just want to buy something, how about a clamping tool guide? http://www.amazon.com/E-Emerson-Tool-C50-Contractor/dp/B003TXSAHU/ref=sr_1_1?ie=UTF8&qid=1424726659&sr=8-1&keywords=clamp+edge
...But, you can really just make a jig that'll do the same thing, ala: https://www.youtube.com/watch?v=oiSz7kPwFY0