i386 with PAE or AMD64 on PowerEdge with 4G RAM

[Martin Turgeon]

Good afternoon,

I just receive 2 PowerEdge servers (a 1950 and a 860) both with 4G of 
RAM. I installed FreeBSD 6.2 Release i386 on both of them. 
Unfortunately, only 3,5G is recognized on the 860 and 3,3G on the 1950.
dmesg on 860:
real memory  = 3757834240 (3583 MB)
avail memory = 3678318592 (3507 MB)

I am facing a difficult decision. Should I use i386 with PAE enabled in 
the kernel (I read a lot of warnings using it) or should I go with 
AMD64? Which branch should I follow?

These servers will be front-end/back-end MySQL(with replication) and 
Apache servers with BIND, Postfix, Dovecot, PF.

There is the detailled configuration of the servers:
PowerEdge 1950
Xeon 5110
4G RAM
PERC 5 Raid controller (mfi)
Dual Broadcom 5708 (bce)

PowerEdge 860
Xeon 3070
4G RAM
LSI Logic Raid controller (mpt)
Dual Broadcom 5750 (bge)

Thanks a lot for your advice,

Martin