there's an app called zedge. i use it for ringtones and text tones. i got the one that the motorolas have. it yells "DROID" at me and is pretty loud (my wife actually hates it it is so much louder than the other tones...lol). download zedge and you can preview MANY tones. when you find one you like you can choose to download it and select it as your tone. keep in mind that these are tones people have shared so there may be multiple files of essentially the same tone. some may make the same sound, but be louder. i also use an app called "missed call" that let's me customize the tones and reminders a bit further than just the phone. so now when i get a text, it says "droid" and vibrates at the same time. it then continues to vibrate every couple of minutes until i feel it in my pocket (i also have i hard time feeling it vibrate OR hearing it when it's in a loose pocket).
Thank you, thank you! Thank you! Probably everyone but me knows this, but I finally thought to search Zedge for 'loud' and got several tones to choose from that have 'loud' in their names, which more quickly let me find the type of notification tones I was looking for. I've started with the loudest 'DROID' one per your suggestion, and see how that works over the next day or two.