hi and welcome!
what you're looking at there is a typical peter laird style ninja turtle. yes jim has drawn some similar in the past but that was early on when he was mimicing what kev and pete were printing at the time. now (and for quite sometime) jim has his own original style in which he draws the turtles. as seen here:
http://paneltopanel.net/wp-content/u...T-VOLUME-5.jpg
i have yet to see a good, legit pete laird style custom. i have considered makeing one myself, but i have a few other renditions i want to get through first. a custom like that is not going to be an easy one. it will pretty much have to be an entire sculpt/resculpt. the neca turtles, while eastman and laird style, are the earllier style of the duo and would not make the best of bases. what you're looking for is more of the later style from the duo (style mainly influenced by pete whether by his pencils or inks). i've been doing custom figures for a pretty long time now and i can tell you from experience, getting one custom figure like that, let alone all four, is going to be expensive. you're looking at somewhere between $150-300 per figure. like i said earlier, whoever does it will have to basically do so from scratch and that takes a LOT of time. not to mention you're going to want to go through someone who is good enough to achieve your goal. there are a lot of great customizers out there and many more that will offer to make one for you for less than what i stated, but can they capture "the look"? that is the toughest part.
there are two types of customizers. one who kitbashes (uses existing parts from other figures/toys, aka frankenstiening) and another who does a lot more sculpting/resculpting. for a project like this you'll want a customizer who is the later as there really is no existing fodder (parts) that best represents laird's style.