Hi Ronand,
Coming from the bizjet world myself (& I love the lifestyle), I would suggest you go for the XLS, however i tend to agree with those who suggest that you go for the 737.
A few hours in the 737 will get you into the biz jet world much easier if you find out that airline work is not for you & if it is .....well you are there already.
We all know that things at Ryanair are not ideal, however in my opinion this bizjet outfit is taking the p&%s when they are asking you to part pay the Type Rating, relocate to Eastern Europe (i guess at your own expense) & the salary is not that great either.....you might aswell provide the lube!!.
Good Luck with your future!