USPS Real Time & Flat Rate together?

I have a client who is currently using the USPS shipping module and it is working fine.

They wish to continue using USPS real time calculation for parcel post (as an option)

However, they wish to add two flat-rate options ie medium or large for priority shipping.

Is it possible to configure Zen Cart in this manner? The customer would have 3 shipping options: parcel post, priority flat medium, priority flat large.

I am thinking that the USPS module would still be used for the parcel option but that I would need a couple of custom flat-rate options ....

Well ... I took a plunge

I am still using the USPS module for priority and for parcel

I am also using the Flat Rate option for one of the flat rates

I installed the Flat Rate Clone and am using it for the other flat rate

everything is all set for the same shipping zone

so far seems to be working ok

Sounds good. Could you post a link or PM me? Would be interested to see it working. Thanks :)