you're absolutely correct, x-over cables are for connecting similar devices. though that was true in the olden days. new devices nowadays have Auto-MDIX, so special x-over cables are not necessary. plain straight-thru should suffice.
do you really need a dual-wan router? those are kind of expensive. unless you really need load-balancing and you sorta have to be fairly technical to set them up.
anyways, if you just need to transfer files while at the same time having two internet connections, just buy a 4-port or 8-port switch, much cheaper. just connect your modems and PCs to the switch. change the internal IPs of the modems to similar subnets (e.g. 192.168.1.1 for modem
#1 , and 192.168.1.2. for modem
#2 ). disable dhcp service on both modems. Your 2 PCs should also have NICs, give them statics IPs (e.g. 192.168.1.3 for PC
#1 , and 192.168.1.4 for PC
#2 ) Gateway for PC
#1 should be modem
#1 and gateway for PC
#2 is modem
#2 . Subnet mask for all device should be 255.255.255.0. So now PC
#1 gets its internet from ISP on modem
#1 and PC
#2 on modem
#2 . Also PC
#1 & PC
#2 can share files, etc. since you're not "tech savvy", you probably need a competent technician to do all that for you. let us know how it goes.
have fun!

Originally Posted by
kirakira
Um, I'm not really good with this kind of thing pero isn't crossover cable used for connecting same type of devices? Kung iconnect computer to computer, asa nako iconnect and two ISPs? Kung Dual WAN Router, ka imagine ko connecting two ISPs and two computers. How about sa crossover cable? Or am I wrong?