Road legal, definitely
You wont regret it!
I found the whole process very straight forward, the dvla can be a pain and there are lots of things to think about for iva but nothing to difficult really, this is how my journey went:
step 1 - I wrote to dvla re chassis no. few days later it was on the doorstep
step 2 - read peoples build diary's and posts who have passed iva, make notes about certain failure points on these cars
step 3 - book iva, bend over to make extortionate payment, take it like a man
step 4 - panic you don't have enough time to get the car finished for test
step 5 - work hard get it done, having a deadline helps
step 6 - wake up iva test day to find out its raining, have a little cry & come to terms with the fact its going to get wet at some point! arrive at iva, pass first time drive back with stupid grin on face
step 7 - drop in at dvla on way back from iva, they wouldn't inspect it and made me make an appointment to go back 9 days later, swear at them, mutter under your breath and walk out
step 8 - attend dvla inspection get numbers checked etc etc all ok, take document to lady at the counter and receive tax disc, excellent
, watch women drop file of all my receipts etc and embarrassingly pick them up
realise that in her haste to pick up my receipts she forgot to charge me for registering the car, say thanks, smile, make sharp exit before she realises
step 9 - go and get number plates made up, fasten them to your car and go and have the most satisfying first drive of your life!
step 10 - blow engine up at track day, install more powerful one over winter