I just use the standard plug that is either hotter or cooler than standard. I think its a 5 rather than a 7 or the other way around. Ring BVM Moto and ask them if unsure. I've never had an issue with the standard NGK plug in this grade.
Get your self two spare air filters of the best quality you can afford. This way you can have a fresh one fitted every ride (useful if Saturday is wet and your out again on Sunday). The second is clean and dry in your tool box all the time and the third is being cleaned and oiled.
Clean with filter cleaner, wash with detergent, rinse really well with cold water and dry overnight away from heat. Once dry get 50ml of proper filter oil and drop it in the bag the filter came in. Rub the bag to coat the insides of the bag in oil. Drop in dry filter and massage all the oil into the filter sponge. Leave the bag sealed till you need it next time. Never bin the bag, just repeat the process. The alternative is spray the filter with proper filter oil inside and out and pop it into the bag and massage the oil in.
When you fit the filter lightly coat the mating surfaces in grease. As these go together it will stop water ever getting through the filter edges and mating surfaces.
Clean filters are essential and not desirable. Dirty filter will mean big problems in years (if not months) to come.