88 & 114 hp are weird sizes - ie not standard rails sizes are you going to use wood rails? - I've tried this and personally I wouldn't advise it - when using aluminium rails (and preferably threaded inserts - seriously much better than sliding nuts) it's much easier to stick to standard sizes!!

For small systems I don't understand the need for fixed threaded inserts over sliding nuts. With the sliding nuts you get a free (well, probably over 1500$) shaker,too!
On a serious note the casefromlake boxes look amazing and functional! I wonder if I should have gone down that route as my system currently would need a case for travel.