It sounds a lot more like the valve failure was the first failure that took out everything else in turn - these don't break the valves if you just screw the timing, but that belt was also WAY beyond the service life of 6 years if it was still original.
The VM Specialist
http://www.vmdieselspecialist.com/ can sell you a head for probably about $400 - take the opportunity to also source a 2-hole head gasket from them since you will be waiting on the shipment anyway, and then get new valves, ARP studs, and rockers from IDparts (the rockers VMspecialist sells may be used) as well as new glow plugs and a new timing kit. You should get all the parts for around $2k
VM specialist also sells pistons and sleeves and rings if you (probably) need that as well. Plan on pulling the block for this.