Blast3r

I'm not sure about their MTA hosts, but I'm more than happy to say that this host is actually great for SAMP servers. And their support is quite fast. I'd suggest you give it a try with colorhost.

http://gtamap.delux-host.com/converter/old/ That's simple mate, just copy what you mapped to the link I just placed and then tick in which one you'd like to convert the map to and you'll get the objects in the right format for MTA.