Alright mate! I had exactly the same idea as you when i first bought my RT. Wanted to replicate a valver though.
Not long sold the RT i had, heres a pic of what it was like before i sold it though
http://www.cruisenorthwales.com/forum/index.php?s=a36671d70fe8ceb85ba3d28276739dac&act=Attach&type=post&id=29642http://www.cruisenorthwales.com/forum/index.php?s=a36671d70fe8ceb85ba3d28276739dac&act=Attach&type=post&id=29642
Doesnt look bad at all really.
The main problem i can see for you is that RTs didnt come in 449 sports blue.
I had mine completely re-sprayed in a very similar colour with a green and purple fleck in. Went to renault & bought 2 front 16v flared arches and a 16v bonnet. Got a 16v rear bumper off someone on here, cant remember whom!
The only real problem with fitting i had was with the rear bumper, as its designed for the valvers flared arches not the puny RTs. I had to mould the original RT side bumper brackets onto the valver bumper so it would fit. If you tighten it enough it pulls it in a bit.
I bought a valver not long before i sold my RT, and ive got to admit that i wish i hadnt spent the money on the RT, because the 16v is just so superior in every way you could imagine! My old RT still looks nice, but put mine and a standard valver side by side and the valver will win my heart every time! Just those seats are too damn comfy!
In other words mate, i wouldnt bother. Get a years no claims on yours, then go straight out and buy a valver! Dont make your car tacky and have everyone saying oh look at him, he thinks its a williams!!!!
Im sure thats something that most people on here will agree on!
Hope this helps mate!
Al