Some other websites you can use for price comparisons:
www.samedaymusic.com (sometimes have good prices)
www.samash.com (sometimes have good prices)
www.music123.com (same company as musiciansfriend.com & guitar center, but might have different promotions)
www.zzounds.com (same company as americanmusical.com, but might have differnet promotions)
www.guitartrader.com (in CA so have to pay tax, but sometimes may have good scratch&dent deals)
The website I recommend the most is musiciansfriend.com because they have largest selection and usually better prices. Perhaps you can use their site to look for the appropriate guitar, and then check other website for price comparisons.
There are two kinds of electric guitars, one has single-coil pickups (thinner sounding), and the other has humbucker pickups (muddier but fuller sounding). Single-coil pickups are closer to Chris Tomlin's rhythm sounds, whereas humbucker pickups are closer to Hillsong United hardrock sounds. I believe our English congregation is geared more towards the humbucker style.
I personally own about 10 guitars, and only use 4 of them for worship (2 humbuckers and 2 single-coils, depending on what kind of music).
1. Epiphone Dot Deluxe: Humbuckers, very versatile, can play jazz and hardrock
2. Epiphone Les Paul Black Beauty: Humbuckers, pefect for hardrock. I use this for United songs.
3. Fender Standard Stratocaster: thinner sound but very versatile and clean sounding (and bright). I use this for mandarin worship.
4. Squier Classic Vibe 50's Telecaster: very clean thin sound, I use it for worship leading where I only strum and no solos
There are plenty of good guitars priced between $300 to $400. I personally would avoid anything below $300 (unless it's a scratch&dent guitar that is originally above $300). I would also avoid any "starter's packs" because they don't have good quality and usually don't have any room for future upgrades (for example, change pickups to better ones).
Epiphone is a sub company of Gibson (very famous), and it plays like a real Gibson. But since it's a sub company, young people may think that he would "lose face" if his friend owns a real Gibson (not likely, but possible). If that is a problem, then Ibanez is another good choice due to its versatility and playability.
OPTION A (AMP ONLY):
High wattage is not necessary. Usually amps are 15watt, 30watt, and 60watt or above. 15watt is good for home use. 30watt is good for onstage monitoring. 60watt is good for onstage monitoring if you are standing close to a drummer.
More options here, they are all pretty inexpensive.
OPTION B (MULTI-EFFECT ONLY):
If you have an existing keyboard amp, then you can afford a good multi-effect unit. Here is a complete listing of what they are. You really can't buy a bad one because they are all very well-built and all have good reviews online. I highly recommend Line6, Digitech, and Rocktron for their user-friendly interface. Boss is way too hard to use (I have a Boss GT-10). Vox has a tube inside therefore is high-maintainance.
OPTION C (AMP AND EFFECT):
You can buy a keyboard amp to go with the multi-effect because they work well together. Or you can also look at some cheap tube amps that don't have built-in effects (because you have your own) that offer a very good non-digital, analog tone.
ps: you can also try craigslist.com for some good deals. There are lots of people selling their used guitars/amps/pedals, can be a good place to start before you invest too much money.