Living not far from you I'll say this. Heim's are not DOT approved. It won't pass inspection in this state. And in this Nazi Lawyer ruled place if you got into a p************* match with a cop or something badwere to happen they'ed hang you out to dry. I'd stay stock or go with some upgraded stock style stuff from a place like Dynatrack. MD is not exactly known for being big truck and off roader friendly.
Nothing is "DOT Approved". It's not like any parts are submitted to the DOT for an approval.
Also, here in MD, and in VA, heims are fine in the steering. I have copies of both state inspection manuals, and neither bans heims. There is a little bit of fuzzy in regards to modifications and aftermarket equipment, but that's fairly typical. I have had multiple vehicles inspected in both states pass, including being looked at by Troopers in both states.
I used to be a VA state inspector, as well.
Now, I could very well be wrong, and it wouldn't be the first time, but I'm fairly certain on this, if for no other reason than I can name multiple cars that came from the factory with spherical bearings/heims in the steering and/or suspension, sealed and unsealed.
ETA:
I ran heims on the steering for my Ranger as an offroad/DD toy, and they lasted about a year in Richmond, with about 10k miles, of which 5k was offroad. The offroad mostly consisted of fast forest roads, with very little rock crawling or mud, and never snow or salt. They were also sealed under a boot for part of the time. The boot made no difference, it was mostly just the load from the tires and the speed. I used quality Aurora rod ends, and they weren't cheap. It was a necessary evil with the travel, however.