nope - all the chips are the same for installation difficulty. Comparing a ps1 chip or even an Xbox chip to a PS2 is like comparing one of those 4 piece puzzles made for children to a 10000 piece jigsaw. The ps1 had a very high tolerance for wire sizes so people got away with 24AWG Wires (about 1mm with insulation - .5 mm without). The Xbox is the same - but many xbox chips are wireless and ps1 chips installed in less than 3 wires for the most part. These are 21 wire chips which are very sensitive to minute details.
The magic 5 is as difficult to install as dms3...but every ps2 chip for North American ps2's has a minimum 20 wires. There are stories of a 14 wire chip for European systems but it sucks.
Magic V, Messiah2, and DMS3 are the 3 best that I know of but DMS is the preferred chip of them all. There is also, i *think* the apple or matrix (i forget), but i don't know too much about them. Either way, expect 21 wires and if you don't know what you're doing, step away from the ps2 my friend...step away from the ps2