I am only vaguely familiar with these engines...
You can't use a roller cam in an early duke unless you buy "linked" roller lifters. The later roller cam engines had bosses cast into them in the lifter area for lifter retainers with a specific retaining bracket.
The after market Chevy roller cams had the these types of lifters. They were linked together with an arm so they could not turn in the bores.
You would also have to re-set your rocker arm geometry by using a pushrod that can be height adjusted to make the rocker perpendicular to the rocker bolt. Then you would have to buy a set of correct length pushrods.
I am running a set of Chevy big block rockers on one of my Dukes... I had to recalculate the rocker geometry and buy a set of Comp Cams special length pushrods.
The fuel pump part is easy. A Ford fuel pump block off plate works well on the Duke fuel pump boss.
Remember to install the fuel pump close to the tank, they push fuel better than they pull unless you have a British electric diaphragm pump.
As far as a carb... I have had no luck with a 2 SE Bogchester - particularly the electric version. If you run a header and big exhaust, you will never reach the full potential of your mods. Why do I know this?
I installed a header on a friends 82 CJ with a Duke. It ran so poorly, I had to install a Weber.
Which leads to the next issue - carb.
I am tired of recommending a Weber conversion, but it is the least expensive and best pop for you buck. They sell the complete kit at many sites including Ebay.
A Duke I built with all sorts of performance stuff...
I happen to have a header for the Jeep Duke. I sand blasted and painted it with high temp paint. I don't know if it fits an S10 - which is what I have, it looks close. I may part with it since I have a very expensive Clifford header.
I would recommend going with a flat tappet cam to avoid all of the possible problems that you will
encounter trying to make the roller unit work correctly. They are inexpensive and you can find a Comp Cams 268 duration for under $150. BY the time you make the roller cam operate correctly, you will have way more than that into the build.
I am also running a Holley 390 CFM 4 barrel on an Offenhauser intake. I also have a Holley 350 CFM 2 barrel as an alternate.
I'll add more if you answer this post.