Neck/back problems: Where to buy a quality office chair?

I've just been told that in an MRI of my shoulder there is evidence of extensive tendonitis and early signs of degenerative arthritis. I spend perhaps 10 hours a day in front of a laptop, and I've never had a chair with neck or back support, never mind any sort of advice about posture and laptop levels. Ordinary office chairs have sufficed until now. I need to change that.

After some googling I see Viking and other companies have a range of chairs for people with neck problems. However, is there any place that's not overly expensive - I'd pay up to a few hundred euro for one - where I can go to test such chairs or better still get advice on what I should be looking for in terms of neck/back/shoulder protection in a good office chair. It would seem a bit insensible to buy such a chair online without testing it, or without knowing what constitutes a good chair for my neck and back.

The Back Shop seems to be the only specialist back shop in Dublin but it doesn't have a price list so I'm wondering with my (rough) budget would I be wasting my time with them? Are there any other options, and what sort of price should I expect to pay for a quality chair? Thanks.