I give you a fairly answer: Don´t buy any of these birds! The Meulemans have no good pedigree and they are to old. At first sight, the Janssen bird makes a rather good impression. The pigeon is not too old and the pedigree looks not badly. But:
1.The fancier say´s he will reduce his breeding loft. In my point of view is this a pigeon which is not good enough for him. Why should this pigeon good enough for you?
2. The forefather´s have not prove their qualities on the race-loft (and this over more generations)! In my point of view this is the biggest problem. Nobody of these fanciers can show you good racing results (actual results of the last years). They don´t breed good pigeons, they only multiple "good" pedigrees.
Summarize I can say, no one of these two seller can show you actual racing references. If you absolutely want to buy one of these pigeons I would buy the Janssen. But consider that the chance of good offspring is very low.
When I buy pigeons, then should this be from lofts who races very good in their region. If possible from the base breeders of these lofts (or grandchild´s of the base breeder).
I hope this help you a little bit by your decision.