I have an '08 Ultra Glide and I need some assistance from you knowable guys. I'm looking to upgrade slowly. I've found a Kenwood KMM-BT228U and the Soundstream PN4.1000D. I plan on adding speaker pods to my lower fairings.

The first question I have is for mounting the amp. The only install amp install kit I have seen is for the Rockford Fosgate. I'm pretty sure I can do the wiring but what about the mount?

I have seen lots of guys recommend Mmats and Infinity Kappa's. I know that the fairing speakers are 5 1/4, should I upgrade to 6 or 6 1/2's?

If I have missed anything please let me know.

 

I have a 10 Ultra and I used that amp for a while. You don't really need a custom mount for that amp in this type of setup. I just used velcro to secure it to the top of the head unit. You may need to trim the plastic on the bottom of your speedo and tach housings to get the amp to slide back far enough to get the fairing back on.

As far as speaker sizes go most of us just use 5 /14 to 6.5 adapters for fairing speakers. That opens up a lot more options. The adapters also move the speakers back a little so you don't have to worry about the tweeters hitting the grills. If you search for some of my older posts from a couple of years ago I put up a lot of pictures of my SS amp install. They will show you how the amp can fit. I got a basic flat plate amp mount off of eBay that gave me plenty of room to tie stuff to.

I will say though that you should consider getting a nicer head unit. The one you picked only has one set of preamp outputs. You already have fader capability since you have an Ultra so I would pick a head unit with two sets of preamp outputs. The SS amp does not have a switch for two channel input so if you didn't get a different head unit you would need a couple of RCA Y adapters to hook the amp up anyhow. If you are planning on just the four speakers up front you would benefit from putting the fairing speakers on the front channel and the lowers on the rear. That way you can blend them on the fly. The lowers typically need to play louder than the fairing speakers to be heard well at highway speeds.

If I recall correctly Fathead Cycles has a decent deal on a Sony MEX-M72BT marine rated head unit with the wiring harness and handlebar control module already assembled and ready to plug in. If you don't want to mess with wiring up the handlebar controls yourself that might be a good deal to check into.
Sony MEX-M72BT w/ Metra 99-9600 HD Install Kit Plug and Play Bundle | '99 -'13 Harley-Davidson

As far as install "kits" go you can buy them but a lot of us just by the Oxygen Free Copper 8 gauge wire by the foot and the RCA patch cables and hook things up that way. Some of the Harley specific kits only come with six feet of 8 gauge wire and the way that amp sits it can be a little tight. I would order eight feet of black and red in case you make a mistake. A lot of folks like Stinger RCA patch cables so a couple of sets of those could connect the head unit to the amp. Then some 16 gauge OFC speaker wire (measure out how much you need and buy extra).

Hopefully if I have missed anything the smart folks can fill in the blanks.

 

Yep, 6.5" speakers are what most of us upgrade to and you will need a speaker adapter.
The Mmats 601.cx are quite popular, and for good reasons.
The SS pn1000.4d works good, it's a little tight, and will probably knock out your radio reception. The Stinger 700 SPX is a little more money, but will not knock out your radio reception. It pairs well and sounds good with the Mmats.
Sony makes a great HU for the bikes. My older MEX 70bt has survived well on my bike for 4 year.