if possible, i'd host your images on the same ip you mailed on, or at least the same domain. Keeps rep contained. Same with landing pages. If you can't host them yourself, I believe there are some sites, some of the tiny url sites maybe, but I've always hosted them myself. Even if you use an esp or other 3rd party service, I'd still try to get your own domains for landing pages, and keep images contained within them. Depends on the kind of mail you're sending but email always looks (and is) more legitimate when it looks like a single website sending to its own subscribers, to its own pages.
I don't understand how image/link hosting would be a problem. With compliant mailing and low complaints you can host just about anywhere.
