Second hand camper or pay for a conversion - which is more cost effective?

I want to feel like I would be comfortable doing my daily domestic activities. Does anyone have any models to recommend?

I found the best Small Camper Van Interior Ideas, and I'm really curious whether I should buy a converted van or convert it myself.

I'd love to do the conversion myself but have to be realistic that with 2 young children and a house that needs work it wouldn't happen!