The one you have is the best one to use.
The ones without the coil in cap are harder to find as they were for A/C equiped vehicles. The caps are indexed differently bewteen the two types, so if you were to switch caps, you need to file a new slot in the housing. Getting the ones with the coil in cap are not hard to find. If the local yards don't have one, Ebay will.
Tom Langdon sells a mini HEI based on the 2.8V6 dizzy for use in the 235/261 type engine. I know it can be made to fit the 250 as well.
Otherwise, old school flat cap Mallorys show up on Ebay occasionally. It can be converted to electronic.
A side note, if you are running the 153 tooth flywheel and you don't want the tranny angled like that, get a 403 bellhousing. They are common as dirt. They sell for $20-40 on Ebay all the time.
