IP subnetting

Hi,

I have a 126 IP addresses on a single subnet all routing through the 
same gateway. I have upgraded my router so I now have 2 interfaces. I 
want to put an SMTP and HTTP server on the 2nd interface and keep the 
internal hosts on the original interface. I think this is basically a 
DMZ configuration.

My current IP address assignment is sporadic, with some static hosts 
at one end or the other on the IP block and DHCP given a pool from 
the middle. 

I want to assign a /29 block of address from within my range to the 
2nd interface giving me 5 addresses to use. I am a little unsure what 
the impact of this change will be on other network services, in 
particular DHCP. 

Will I be turning my simple single subnet into 3 different subnets? 
Do I configure my dhcp.conf with 3 subnet declarations? Can 2 subnets 
share a gateway address even if it's not local? Would it be advisable 
to re-configure those static hosts at one end of the block into the 
other end so I only have 2 subnets? What other services might be 
effected by this change? I can think of a few httpd.conf allow 
statements that might need changing and possibly some smb.conf 
changes. 

Thanx in advance,
Dp.