A couple of things i'd say.......

1. If you want to run 40 dcoe's, then you really need at least a modified cam and ported head, otherwise you wont really see the benefits of fitting them........

The carbs have 4 seperate barrels, each allowing the optimum airflow matched to the jetting (you will need this setup on a RR), however, you do not increase the airflow (cam and headwork), you'll basically just end up running them setup like the standard carb, so no big differences....

2. Pump is a good one, i always used to use the Malpassi Filter King regulator (good bit of kit).
I'd wire the pump through the igntion and a Switch too.
Hide the switch somewhere (just the dash for example, but somewhere you can reach when you get it), that way you can isolate it should you need to, but also you can turn it off when you leave the car, so if anyone got in and tried to start it the pump wouldn't run........

Assuming you dont yet have a Cam or any headwork, i'd am for a Fast Road spec cam, and to make use of the carbs, ported head with bigger inlet valves.........

Dont know what your engine puts out as standard, but the very first engine i ever built was a 1300 x-flow.......
made 115bhp on 40 dcoe's.......

3. Dont forget though, once all is fitted, you'll need to get it to a RR as the choices of chokes, emulsion, accel jet and mains will depend entreily on your engine spec.........

I'll never forget my first trip with the above x-flow....
it was spitting and coughing all the way there.........the drive home home was brilliant, smooth and so much more powerful........

Hope that helps.