No Quarter

I'm not too keen on the ideal of paying $100+ to obtain a Serial Link box to tune the Miata Link ECU via PC that came in the 96 NA8 I just picked up with a FM2 turbo kit but I currently have a MS1 PNP for 96-97 NA8's and I'm wondering what I need to look out for in switching. Alternatively if anyone has advice on building your own Serial Link I'd gladly take all the information you can pass my way, I'm not shy with a soldering iron I just lack the information on whats actually inside the serial link box.
I've been reading up into both but first hand knowledge from the legends of the turbo Miata world here on Miataturbo.net would be invaluable in helping me from making and newbie mistakes.

Yes I know both ECU's are dated and that MS1 isn't the best option but its easier to find someone that tunes for MS and its $15 for a tuning cable for the MS1 vs $100+ for a Serial Link if I can manage to find one for sale alone and not with an entire Link ECU.
Mostly are there any wiring changes that need to be done/undone from the process of installing the Miata Link ECU?

Thanks in advance for the help!
First post, sorry admins if I mucked something up! :-D
Edit: I found internal pictures of a Serial Link and its not just a pass through as I was hoping sadly.
Here is a link to internal pictures of the serial link, map/knock box and the link hand held controller if anyone else was wondering as I was. http://www.hendy.com/link.htm