Damn, got up early to watch the Monaco GP, but it's a delayed telecast. I'm a big Ross Brawn fan. Race is on at 7:30 instead of the normal 5AM.
First let me qualify tire selection answer to avoid all the flack I've been getting lately. As some of you may know from my exchanges with Tony, that I like Spec tires, but we were wearing out the new S-Grips twice as fast as the old ones. I also did not like the way they made my cars "feel". Ideally, my choice of tires would have the identical set up as with the S-Grips so there needn't be any set up changes when switching from one to the other.
For 60D tires, my choice is the Pit Shimizu tires. They come in 4 different compounds from hard to super soft. The hards are the 456 and go down to the super softs which are the 450s. The safest combination is the 456 in front and the 452(soft) in the rear. A faster combination is the 454(medium) and 452 rears, but your car needs to be on the dot as far as set up goes to run this combo. I have not tried the 450s, but since were going into hotter weather, probably won't. These tires are also $3 or $ less per pair and last at least 2 or 3X longer.
For inserts the most consistent was the Tamiya hard inner sponge #53255. The best rim I've tried with these tires are the Suzuki Swift rims, but the 11spoke rim #51394 seems to be as good and are $4 less.
I purchased mine from TQ and from Speedtech. TQ has them in stock and Speedtech can get them for you. Jeff at Speedtech said he would stock them when we talked at the last race.
55D tires are a whole different world. Many of them have to ordered from HK or in one case from Australia, I think, but am not sure. All sorts of different inserts out there too. Just off the top of my head I can think of 8 different tire makers and molded inserts in 4 different thicknesses and 6 or 7 firmnesses. I wandered into that rat race a few years ago, spent a couple of thousand $$$$, got out and gave most of them away.
For 55d tires I use Sweep premounts, usually the 40 in front and the 33 in back. They are readily available, about $25 for 4. Many shops and retailers stock them and can be purchased direct. There are better tires and tire combinations out there, but I've not been willing to chase them.
Hope this helps and good luck.