Look into making or buying some rayu (Japanese chili oil).
It's fairly easy to make and a nice thing to have in the pantry. And at least for me, once you start making one, it's hard to not go a little crazy and start making others (sichuan peppercorns etc).
http://www.seriouseats.com/recipes/2013/12/homemade-rayu-from-japanese-soul-cooking-cookbook.html
Kadoya is my favorite brand of sesame oil to use.
S&B sells a brand with crunchy garlic... when I make rayu I like it to be spicier, but it's still pretty damn tasty and a nice snack on a bowl of rice. My local Asian supermarkets stocks it although it's still pricey.
https://www.amazon.com/dp/B00BF028XQ/?tag=skimlinks_replacement-20
I've never had spicy salmon but for spicy tuna I like chili oil, kewpie, green onions, fried garlic, sesame seeds, and soy sauce. When I'm making sushi I'd rather splurge and get really good quality fish and use more soy sauce and less mayo. Drenching just mediocre fish in spicy mayo can leave you kinda grossed out at home...
My advice would also be to try your hand at doing temaki/hand rolls. It's actually how I prefer to eat spicy tuna and can be less intimidating than trying rolls. Get good nori, make a spicy salmon/tuna/tako mix that you enjoy, cut up some veggies if you're feeling fancy, make some nice sushi rice (or at least try :biggrin
, and then stuff your face. It can be fun with friends too - everyone giving it a shot & playing with their food.