i second what most people have said here about transfering. Heck, a good part of my guild's recent recruits came from guilds who thought that transferring to gurubashi would solve their problems.
Its not that I doubt your guildmate's loyalty, but think of it this way: what if, after you transfer, you don't experience the sort of influx of applications that you hope for? Many potential recruits are looking for guilds that are raiding regularly, and most, if given the option, will prefer to go to an established guild than to one that has 18-20 (great as they may be) raiders and needs additional recruits to raid at all (as opposed to needing more recruits to have some cushion and be able to raid regularly). Will your folks stay with you even if it takes a week to form a good group of 25 people? Long waits for potential recruits can be more frustrating than doing unsuccesful runs with unexperienced members, and just one defection in that time period can be enough to destroy morale and start a mass exodus.
So unless you are certain that your core group will stick together even if it takes a couple of weeks to raid again, avoid this at all costs.
My guild formed by merging in a server xfer from some old friends we knew.
Basically, we do almost no on server recruitment unless someone personally knows the person. We are 2/3rds thru BT and the next best horde guild is on al'ar/solarian, so basically, we have no app pool on server.
95% of our apps come from cross server, and it is absolutely amazing how talented many of them are. If you want serious players, look cross server for people who share your mentality.
The other option (I suggest doing both) is to search through threads of people LFG. There's a smaller audience, but it's targetted and you do get some good apps trolling those posts, too. If you see someone LFG that you think is a fit for your guild, link them your recruitment post.
I will double-stress this as a great way to find candidates. I did the "baby-sitting our general application thread" thing for awhile, but by far we got better results when I took the time to dig through the individual LFG applicants and taking the time to see if they were a good fit.
Another piece of advice, is just to be brutally honest and personal with your message. If you're trying to recruit an individual - don't give them a copy-pasted reply that doesn't address any of their points. I see this all the time and it's just embarassing when an EST PvP guild posts a "hey check us out" standard message on a thread that's titled [A] Shadow Priest LF PST PvE guild. The more you sound honest, up-front and personal, the better your response rate will be.
And yes, some of our very best applicants came from two pools:
1) Cross server applicants
2) Skilled friends/family of current guild members
Regarding #2, make sure to stress to your guildies that even if someone is a friend, if they suck they won't get in. Friend-ism/Nepitism is great in the office and in politics, but not so much in a raiding guild =)