Back when I still did OTMs, as the admin, I would usually do the graphics myself, just because no one else was really around to do it/wanted to do it. :'D

Graphics commissions are a little less likely than skin commissions, and would at least definitely be cheaper just due to the fact that whipping up an image is usually much faster than whipping up a skin (at least for the level of graphical complexity that most people in the community tend to use - Mizo's graphics go HARD, so those might take as long as a more minimalistic skin, I dunno). At the very least, I don't think asking for someone to make graphics for free is that unreasonable, although offering payment would probably make people more interested in taking you up on said offer. Not that I think that's... particularly worth it, especially if all you're looking for is a nice crop.

You could hire a graphics mod either from or for the site you want to do these on - someone who's only job is being in charge of making images. Hosting an ad both on your site and in the staff search board here on P2 could work toward finding a permanent, or at least semi-permanent graphics-maker. Otherwise, if you're not too worried about visual cohesion and don't mind wait times, you can post in the requests board for the images on a month-by-month basis, but the amount of time it takes to get these fluctuate so much that for something that needs to get done on a monthly/timely basis, I probably wouldn't recommend going that particular route. :'D

Absolute worst case scenario, if you've hunted for a graphics mod for a while and still aren't having any luck, just shoot me the image dimensions and the images you want cropped over Discord and I can make you some pretty basic OTM images. o> I like doing tiny things, like icons and avatars, so while they wouldn't be the most mind-boggling images in the world, it'd still be something to tide you over until you find a permanent graphics maker, yeah?