2D Top down Sprite Sheets

I am currently writing a top down 2D shooter and have the following art requirements: Requirements Summary ==================== png format. transparent background. 2D. Top down view from directly above. Sprites to be north facing (no rotation required). frames must be in a single row, not column. each frame must occupy the exact same amount of pixels and have equal spacing. walking sprite sheets must cover a full walk cycle with enough frames to keep it looking smooth and natural when looped. at least 128x128 pixels per frame (should be scalable down to 32x32 without losing too much detail). Power ups and collectables animations should pulse slightly. Power ups and collectables animations probably don't need to have more than a couple of frames. The health, weapon and ammo power ups/collectables don't necessarily need to be sprite sheets, a single image would probably do. Must be decided though prior to project start, otherwise sprite sheets are assumed. Health Power Ups Sprite Sheets (3 sprite sheets in total) ========================================================= First aid box Bandage Needle and syringe Weapon Power Ups Sprite Sheets (4 sprite sheets in total) ========================================================= There are four types of weapon - 1. Fast Shooting gun (700rpm) with a single stream of bullets. 2. Fast Shooting gun (700rpm) with a treble stream of bullets. 3. Slower Shooting gun (450rpm) with a single stream of bullets. 4. Slower Shooting gun (450rpm) with a treble stream of bullets. For the fast gun a minigun style picture, but with enough differences to not cause an IP issues For the slower gun an assault rifle style i.e. AK47 or AR15, but with enough differences to not cause an IP issues For the single shot, a small overlay of the gun in the corner with a single bullet. For the treble shot, a small overlay of the gun in the corner with a three bullets. Ammo Box/Magazines/Clips Sprite Sheets (4 sprite sheets in total) ================================================================= Ammo for +20 Ammo for +50 Ammo for +100 Ammo for +200 For the +20 a small clip/magazine. For the +50 a bigger and different style clip/magazine. For the +100 a brown cardboard box For the +200 a steel ammo case/belt feed. These are just my idea on how I would like things to look. If you have any better suggestions, I'm more than happy to listen. Proof of past artwork required. Previous experience of sprite sheets preferred.