Excellent pick for your first two. Mine were the Black Lanner (just before is was archived) and the Blood Asp, 2nd Sculpt. If you can avoid the 2nd sculpt, do so. Although it looks sweet, it is a pain to build, and I had to fight with it the whole time. I've experienced the same thing with the reseen Warhammer, and I hear many of the other reseen IS 'Mechs are the same.
The best luck I've had assembling a mini was with the plastic Thor that will come with the new intro box set. The best pewter mini I've had so far, as far as assembly and mold lines go, was my Black Lanner. Granted, I don't own as many minis as most of the guys here.
I hope to see you post your minis when you're done with them.