In Silvermoon I have something of a reputation for making the website graphics, and sometimes people consider me an artist. However, most of what I do is just tricks with layered filters, rendering, resizing, and special brushes to achieve the effect I want. I'm far from being an artist, and have gone my entire RP career finding abstract pictures of what Jason should hypothetically look like. It would be really nice if I could get one specially made of him.
He can, and does, wear all sorts of casual dress ranging from shorts, sandals, and a T-shirt complete with sunglasses. But he does have two work uniforms that he most frequently wears. Either one would be valid, and whichever is easiest for you as an artist would be a-ok with me, should you be interested.
Battle Dress UniformSoldier's attire patterned after twentieth century design. A helmet, fatigues, and boots all in one flat color with no camouflage pattern. A rough representation below.
High resolution image of a painting featuring a number of soldiers wearing such a uniform from different angles and poses. Trying to avoid breaking the page.The second component of the uniform, and by far the more complicated, is a bandolier bound to the waist covering the belt. It is a unit that he uses much like batman uses his utility belt - almost everything that he needs to procure, he does so from his belt. From communications equipment, spare ammunition, his sidearm, auxiliary melee weapons (Trench spade; truncheon,) lighters, flairs, hand grenades (in the same vein as the 1940's German 'potato masher' offensive grenade,) etc. So much so, in fact, that the canvas under all the items is hardly visible. But for all intents and purposes for viewing from the front, these are irrelevant. Most of it is on the sides and rear of the arrangement with the various pouches in the front. The only thing that isn't a generic pouch, and is within immediate reach, is the holster for his revolver. The revolver, itself, is nothing special. Pics below.


With this uniform he will always have a long rifle slung over his shoulder via a canvas sling extending from his right shoulder to his left hip. For all visual intents and purposes, it's an M14 that's been souped up to function in TK. Pics below.
Click here. Posting the image will break the page.Dress UniformThe alternative, equally valid, is his formal officers' dress uniform. Picture below - hat is a peaked cap.

If you need it larger, I can do that. I just ripped it off the SMK website for speed's sake.
Either way, Jason is for the most part a happy individual. He should be smiling in the picture; ideally standing tall and confident with one hand/fist/wrist planted on his hip while the other is lifted in a 'thumbs up' gesture. A wink wouldn't be out of place, given his enthusiastic nature.
Inspiration for facial features can be seen here:

[Edit] Had to add something.