+1 for Simtech
I did my MCC/JOC over there last year and found the quality of training and instructors very good. Most of the instructors are experienced airlines pilots : captains from Easyjet, Stobart Air, Aer Lingus...
Also Simtech was used by Ryanair until a few months ago for their sim assessments.
Pros : Good quality of training
Reasonable price which includes hotel + transport
Cons : It's a fixed based generic B737-800 sim, not full motion
That said if you have a higher budget, CAE OAA Brussels does MCC/JOC for 13.000 € on full motion B737-800 ... Some people say it is better to do it on FFS because that's what they use on assessment... but I used Simtech and passed my airline assessment on a full motion sim... Not worth the extra money for a FFS in my opinion.