If you don't want to do the office he wants and have a different kind of idea for him you can just re-do it right after. That's what I do usually. The closest thing to that I've done was a therapist for I think graham or something? but I am not done with it because I intend to expand on it.
Ricky is my favorite villager so you're in luck.
For his house I just spammed the items he wanted and finished, and the came back later, ignored his request, and gave him a house based on his NL style. Not sure what the code is, but here's a pic from miiverse.
Cabin/western theme goes really well with Ricky.
If you actually want to go by his theme tho, the Japanese website has a nice little sample for his home