Good for you mate, I think if you aint priced for a contract yet your safest bet would be to take on board what the others have advised, find out as much info as you can about time scales or deadlines, will you be doing all the kitchens back to back, or will you have a dozen on the go at one time which would mean you have to get other tilers in which will take you time and cost a bit of money which all need to be put into your quote. There is loads to think about so just ask loads of questions as to how he wants it done then take it away and post it back on here.
Im sure others on here could advise you on a few more questions to ask, seriously mate be very on top of it and please remember that although this is a great opportunity and is much easier to do than you might think, these big contracts can sometimes end up costing you money if you get them wrong!! Get all your info and bang it back on here and we'll help you sort it. Good luck Pal it's good to see someone doing well.
TJ