The largest HAA company  

will give you 2 flight suits, helmet, helmet bag, $100 annual boot allowance, and will issue a jacket when you get to your base (pilots get leather; can request the crew type nomex if you want a lighter jacket instead; some programs have non-flying jackets to issue as well (non-nomex)).  

No gloves but nobody cares if you want to wear some old ones from mil days.

Most programs have some form of ball cap to issue and northern regions may have fleece/knit hats for the cold.

You can wear your own ballcap usually and ANY form of shoe or boots (as ridiculous as that may sound; it's true).  I've seen all types of colored ballcaps and every form of shoe imaginable.  No standardization there unless it's a hospital based program then I'd guess there would be more specific guidelines.  

Every base has a day and night iPad with Foreflight so save your money.  Use or any free Wx app to check weather before you come to base.  Can use Skyvector.com (via any browser) to also check weather, see radar, or do quick flight planning to see how long a flight may take if you need to figure out times before accepting a ferry flight if you get a last minute call on your off day.

They'll have an iPad strap or iPad kneeboard to use for them as well if you like to use them.  You can use your own kneeboard and just leave the iPad in the slot for it with other paper docs required in the aircraft (checklist, LZ lists, IIMC card, etc.). 

Your base will have NVG mounts but you may want a weight bag if the base doesn't have the extra battery pack mounted weight screwed/velcroed to the bottom of it (some bases do; some don't; some people just want more weight).  

No lip-lights or flashlights provided.  

Good luck