You might consider a used 7 mm Nagler Type 1. I've very much enjoyed using mine these past twenty-five years. Stars are point-like to the edge with both a 14.5" f/4.5 scope w/Paracorr Type 2 and a Stellarvue 125 Access (f/7.75). Eye relief is a really nice 16mm and there is no kidney beaning apparent at this focal length. The eyepiece is relatively lightweight, wholly unlike the Nagler 1 and 2 series in longer focal lengths.
Also, for more money of course, I've been very pleased with the Pentax XW 3.5 mm. If anything, stars are even sharper to the edge than with the Nagler/Big Barlow combination but of course the Pentax has a narrower 70 deg AFOV, as opposed to 82 deg AFOV for the Nagler. Given the Pentax is a more modern eyepiece, I would guess the coatings are a bit better and so too would be the throughput. I can't tell the difference, though. Best of all is the great eye relief of the Pentax, especially if you wear glasses while observing.
I am an eyepiece manufacturer agnostic. However, one advantage to sticking with one brand is your set is more likely to be near parfocal (same focus point). This is definitely not the case between the Nagler Type 1 and the Pentax.
Depending somewhat on your age, you may have trouble with floaters using ANY eyepiece with an exit pupil less than about 1 mm, so be warned.
Happy observing always,