Wireless N is better in the sense that it has more potential (theoretically up to 300mbps) than G (theoretically 54mbps), but if you're not transferring local files, G is probably sufficient since few ppl get more than ~10mbps from their ISP (often less, esp. w/ DSL). IOW, the ISP has a smaller data pipe, so most of that potential by N goes unused (at least for Internet access). Yet, N can still be useful since N devices tend to have better antenna solutions, even if you only use them in G mode. That helps signal strength, range, etc. Of course, in a mobile home setting, that’s probably not an issue.
N prices have been dropping quite a bit over the past couple years, almost to the point where you can pick up a single-stream (150mbps) N router for the price of a mid-range G router. So under most circumstances, N is probably the better decision. Better technology overall and provides you some future-proofing as well. But in your particular situation, if you only need it for Internet access, and looking for a budget solution, a G solution will more than suffice.