Outkast said it best. The 'issues' with the Clayton kit are tire size related, or up travel related. At 4.5" I think you'll be fine. Fwiw as soon as I get my axles done I'm installing the Clayton 3 link (with some custom aluminum links) with about a 4.5-5" lift. I'm not the least bit concerned. A friend of mine has like 6.5-7.5" lift and 33's with cut fenders (so lots of up travel) and his has just barely kissed the floor a couple times....
Now, the b. Lee 3 link. It looks ok, but I think you could get a better kit. As far as heim size, don't let people scare ya, all this 1.25 heim stuff is a fad that has spilled over from the ultra 4 guys. I have to laugh my ass off when I hear guys say 7/8" is too small for a Cherokee with a Dana 30 and 33-35" tires. My rock rig is a tj buggy with a v8, stak 2spd, lots and lots of tube, full hydro, d60 front, 14 bolt rear, coil overs on all 4 corners and front and rear 4 link. Guess what, all 16 heims are 7/8's, it's heavy and it gets the shit beat out of it. Never once had an issue.
Ultimately it's up to you.....