If money isn't an object, not that they need to be any more expensive than branded lines, get one made to your own specs by
https://www.pcspecialist.co.uk.
You can pick everything yourself or they'd be happy to advise you on everything, just tell them what you want it for and they'll do the rest. If I had the time and inclination I build my own, it's not that hard but I prefer to have them do it because they test it before release and I've got comeback if anything goes wrong.
I've had a gaming PC made by them in the past, a desk top and a laptop and they've all been brilliant. Don't be put off by their nerdy looking website, they deal with everyone from novices to top spec gamers and graphic designers.
One bit of advice I will give you if you go the high street way is don't be swayed by huge capacity hard drives, some offer terabytes of storage and you don't need it. No-one should be storing huge amounts of data on their daily use computer hard drive it's unsafe both in terms of data protection and hard drive crashes.
250 gigabytes maximum is more than you'll ever need to run a machine at opitimum, store everything you want to keep on a seperate drive. Also when you want to scrub your machine thoroughly, which everyone should do at least once a month, it takes far less time.
Also, some of the genealogy software that I use is for Windows, and I don't really want to have to replace all that with Mac versions.
