When I moved to Ukraine I used a 5-year multiple entry business visa. Most agencies will find a business in Ukraine that will send you a letter of invitation. Looking back, though, I probably would have gone for the private 5-year visa. With the business visa you must leave the country every 6 months, even if only for 5 minutes. With the private visa this is not necessary but you must register every 6 months. IIRC, UK citizens cannot get a 5 year visa, only a 3 year one, but the rules would be the same.
Your opportunites for work will be extremely limited if you aren't fluent in Russian but there are several options depending on your education, work experience and where in Ukraine you choose to live. ONce you decide where you will be living I can perhaps help you know where to look or what your options are.
Having a Ukrainian wife is a big plus when applying for permanent resident status but does not guarantee it. Still, I don't know of anyone who has had any major problems with this.
Provide more details about yourself and where you are planning to live and I can provide more detaied information. you can do this through a PM if you wish.
I have never once regretted moving to Ukraine. It takes a lot of flexibility and adaptability, and I know of several that couldn't handle it, but I also know several who feel as I do.