[c-nsp] 12.2SRC or 12.4T for 7200VXR NPE400

[Forrest W Christian]

I've got a couple of 7140's at my edge today running an older copy of 
IOS with no support for IPv6, or long ASN's.  Not to mention a few other 
features I'd like.

I've acquired a set of used 7200VXR's with NPE400's.    As a result, 
it's time to figure out what version of the IOS - and probably what 
package I need.

The must-have features in my mind are:

BGP4  w/Long ASN
IPv6
IP Traffic Export
Support for POS and ATM interfaces.
Smaller-Footprint (memory-wise) since I'm running on a platform with 
only 512MB..

The feature navigator is no help whatsoever, especially since it doesn't 
seem to think that IP Traffic export is in any version other than 12.4T 
(or 12.4 Enterprise), and I know for a fact, from the release notes, 
that it is in later versions of 12.2S (but not necessarily SRC).   Of 
course, that doesn't help me figure out the packaging.   

Plus, since it appears that 12.2SRC is actively maintained, perhaps I 
don't want or need to be on 12.4T.  It also appears that if I want to 
run IPv6 on the later packagis, I need to upgrade to the advanced IP 
services package.

I'd appreciate it if someone could take a minute and help me understand 
the percieved value of the 12.2SRC versus 12.4T chains, and perhaps 
point me in one or two directions to investigate?

Thanks.

-forrest