As per their website, Sportsmobile (They are in Indiana, California and Texas) does fixed high tops for not only Sprinters, but also Chevy/GMCs and Fords.
I got my GMC penthouse top done in Indiana and they did a great job.
Spring has sprung in New York City area. Its above freezing every day now. And the red-wing blackbirds came back a few days ago (2 weeks later than normal).