Hi Rob
Best place I've found to book golf is on www.clubmurcia.com from which you can book any course in Murcia, often at discounted rates. I have dealt with them a number of times and have always found them excellent. They will also amend your booking if they can find a cheaper rate on a course you have already booked.
The only point about the course on the resort, is the guys might get a better rate if they can use the resident rate although I'm not sure if they will be able to if they are renting. Club Murcia does offer a twilight rate for Alhama as well which is cheaper than the usual rate.
As for club hire, there is a hire company on the resort www.condadogolfclubhire.eu but I have never used them so can't comment on what they are like. Another option is www.clubstohire.com - they will meet you at Alicante airport with a set of clubs but again I've not used them as we tend to take our own clubs.
Who are the guys flying with? I only ask as BA let you take your clubs as part of the one free piece of luggage subject to weight restrictions. Easyjet and Ryanir, you obviously have to pay !
Hope that helps!
Cheers