Few jeep questions/opinions

[ShortTemperd]

Looking to replace the shackles wondering if you guys know any good brands are and what are not good, looking towards the boomerang shackles to get more flex.?

Also im looking for 6" shocks for the front same situation whats the best bang for the the buck.?

And last but by far the least what spark plugs u suggest was thinkin about the e3's but its hard to get a good honest answer off google    

Stupid questions but dont wanna go waste money only to be disappointed.  

Any other tips for my jeep build about ANYTHING will be highly appreciated
Thanks  

[Merc09]

Ive had good luck with e3's never used em in a bogger but my street truck they work great.