Hi, any 19" shelving measured in U's should work. Generally shelves sold specifically for "data" come at a premium (but are probably more robust), but shelves aimed more at the audio market should be cheaper and sufficient. I've used
proaudiostash a number of times who have a good range of products at a reasonable price. Think they also trade on ebay. Vented shelves would probably work best for better air flow. Provided your equipment is less than 18" wide to allow some gaps at the side it should be fine.
Rob