I do believe it is possible, but I believe it would suck you dry of your energy or you would die of old age first lol. Think of how long it took you to become the being you are now... depending on how complex in appearance you've made your servitor (some are blobs, some scary, some cute, simple, detailed, it's really up to your imagination) you will have quite a bit of time ahead of you before it is full, physical flesh. Think of it on a scientific level: you would have to manifest each and every one of its cells, its atoms, its bones, whatever. Try to just manifest a fingernail, or a segment of hair, lol. If you can do that I'd say go ahead making your servitor physical... it really is your personal choice, I'm just giving you my take on it.
A servitor needs a 'food source', usually its creator unless specified otherwise. The more advanced and developed it gets, the more energy it needs, and like a child, or more accurately a servant or someone under your command, there will be a day when they realize they could easily kick your butt.
No I have never actually seen or heard of it done, but I suppose it is meant to be that way. I know I would never tell ;)