Low tech kind of guy...does that mean you don't have a Smartphone? If you do, one option you have for GPS is the WAZE app. TBH, I like it far better than my Garmin units. Now, since you don't ride with a headset, you'll have a problem hearing audible directions coming from your phone but you can just see what you need on the screen.
OTOH, if it's a dedicated GPS unit that you really want and you don't mind the cost, you can go with a Zumo. Of course, you can use less expensive Garmin units but most are not waterproof. If it's important to hear audible directions, you can achieve that by installing a BT receiver on your bike which will enable you to connect with your GPS and play it through the bike's audio system.