Hi,
I worked as a freelance FO on the XL and XLS for a number of operators. I started with 250 hrs, flying in Europe, but I had some help. With your hours you should be fine. Try Expedite Aviation, they need freelance FO's on the Excel and XLS. Only choose EBJ as your last option. Try Eurojet they have some XL's.
I used to work for EBJ and they aren't the best company to work for but if you need to build hours go for it. Any questions feel free to ask me.
it is a gamble to pay for your own rating but it is worth it. There are a lot of jobs on the Excel and XLS if you look hard enough and meeting the right people is important.