I would definitely say that you are a good runner, based on your two recent 50m reports, and you are more than ready to tackle a 100 in a few months, but give your body some time to recover from those 50s first.  The first 100 is all about running your own race and getting to the finish line under the time limit.  No 100 is easy, but you can gauge the difficulty of each one by comparing course records on the run100s site as well.

Thanks for the great advice.  I'm looking to run one sometime from next spring onward, so I have time for a few more shorter ultras and then adequate recovery.  If anything, I tend to be overly cautious jumping distance.

Yes you're nuts but so is anyone that runs a 100 miler.

 

I have no experience on any of these courses but your logical choices are as follows:

 

OC 100 http://www.oc100.org/ (October) - NW PA

Burning River 100 http://burningriver100.org/ (July) - OH

Vermont 100 http://vermont100.com/ (July)

NJ Trail Series http://www.njtrailseries.com/fair (March)

Beast of Burden Summer & Winter http://summer100.com/ (August) http://winter100.com/ (January) - New York

Virgil Crest http://www.virgilcrestultras.com/ (September)  New York

Viaduct 100 https://sites.google.com/site/viaducttrailultramarathon/home NE PA

Umstead 100 http://www.run100s.com/ut100.htm (April) N.C.

Pine Creek https://sites.google.com/site/pinecreekchallengepa/ (September) Northern PA

Philadelphia 100 http://philly100miler.weebly.com/ (April) Philly, PA

Old Dominion http://www.run100s.com/od100.htm (June) VA

MMT 100 http://www.vhtrc.org/mmt/ (May) VA

Grindstone http://www.eco-xsports.com/ (October) VA

C & O Canal http://cocanal100.com/ (April) MD

 

 

Could have missed some but this should be a good list to start comparing courses, times of year, logistics, etc.  OC 100 probably is one of the better choices though as Kelly said.

 

Good luck in choosing!

Scratch Vermont 100 and Old Dominion 100 off this list because they both require a sub 24 hour finish to get your buckle. You don't need that kind of pressure for your first 100. Truth be told, I didn't need that pressure when I ran those races.

Beast of Burden, C&O canal and Philly 100...the courses are terrible!

Virgil Crest 100 is REALLY hard. Not a great 100 miler for your first.

MMT and Grindstone are really brutal too. I wouldn't suggest them for a first 100.

The remaining races just need study and consideration. Of course, this is just my opinion.