I have bought from Avery, Brown, Cleaveland and ClearAir as well as Ebay. On Ebay, you need to check out the seller & watch the tool descriptions, know what your are buying. Toolsez seems to have a good reputation & they sell "kits", so a drill may come with a couple dozen bits.
I have had good experience with the regular suppliers listed above. Go to Cleaveland for their "Main Squeeze" if you don't buy a pneumatic. Buy the adjustable set holder if you do go pneumatic.
Chicago Pneumatic and Ingersoll Rand make good rivet guns. My very experienced IA who does museum quality work (he now works at a museum, actually), says they are the best and that CP is the better of the two. Go for a 3X. I got my IR gun off Ebay for $35, but they seem to go for a lot more, now.
The little 3,600 rpm Sioux drill is very well thought of, but there are other good drills out there. On Ebay you will find small Dotco and Rockwell drills. Small size and rpm's greater than 2,500 are good criteria. The little Chicago Pneumatic has bushings, not bearings. May last till your plane is built, but if it doesn't, it is cheap enough you can buy another and still be money ahead over the Sioux. Brown has the best prices for the Sioux. I think IR also makes a small drill now.
Also, Brown has sales. Watch them. I bought a lot of clecoes from them for less than $.30 each when I started. BTW, so far, I have needed a lot more 3/32" clecoes than 1/8".
Clear Air has the best prices on squeezer yokes and pneumatic squeezers, although Brown met their price on a sale. Fred at Clear Air persuaded me to go with reamers rather than using drill bits for match drilling and I am glad I did. The holes come out exactly round every time. Also, I have match drilled everything up through the wings, not including the flaps and ailerons, and my first 3/32" reamer probably needs replacement. I can feel it enlarging the hole when I run the reamer farther in than I normally do, suggesting the first half inch has worn somewhat. Unless I break one, I probably won't use more than 2 or 3 reamers for the whole plane, so the cost is minimal.
Also look at "The Yard", (yardstore.com) for bucking bars--best selection and used to have the best prices. Avery's selection has improved. I have never found a use for their #620 however, even though it looks like it ought to be very versatile. The heavier, the better when it comes to bucking bars.
I was surprised to find Aircraft Spruce had the best price on the Rolo-flair flaring tool. $78 including shipping, $89 at Avery and around $95 at some places.
Lastly, as I peruse the package deals that each of them offer, I find that none of them offer the best of everything. For example, the best hand squeezer is the Cleaveland Main Squeeze, but some of Avery's other tools are better.