I'm sorry, but I disagree with what everyone is saying. Now that your baby is 8 months old, you really should be starting to transition to a regular schedule of food. Not a ton of food, granted...he still needs plenty of formula or breastmilk...but 24 ounces a day is enough. That's 3 eight ounce bottles. Most people give a lot more than that.
Here's my experience...baby number one had no teeth until she was a year old, and I was so afraid she was going to choke, I just didn't want to give her table food. And she really didn't go for baby food...I THOUGHT she just didn't like it. So she did pretty much all milk until she was a year and a half old. It took me FOREVER to wean her off nighttime feedings, and she is an extremely picky eater because she didn't have a good start with food. However, she still LOVES milk, big surprise.
Now, baby number two...I was so determined not to make the same mistake. Exclusively breastfed, but I started foods very early...rice cereal at four months, fed with a spoon...and probably only a teaspoon once a day. Now, she is 10 months old, and eats three regular meals a day. Baby cereal mixed with fruit for breakfast along with a handful of cereal for her to feed herself (Cheerios, for example) and a cup of water. Lunch is baby food veggies and half a piece of dry whole wheat toast, or half a banana. Dinner is baby food veggies OR cooked soft veggies, cut up, usually both, and some other grain...another half piece of toast, little pasta, a vegetable mum mum, etc. She nurses in the morning, before first nap, after lunch, before second nap, after dinner, and at bed time...so, six times a day and she averages 4 oz (I know because I had to pump for awhile, and that's what she drinks.) per feeding...so, 24 ounces a day, and of course the three cups of water (which are more for practice, she doesn't drink but maybe an ounce or two.)
Now, here's the difference...baby number two is bigger than number one, but not NEARLY as chubby. She is just tall and healthy, she eats SUPER well, she sleeps well at night, and she isn't attached to a bottle or sippy cup. She'll eat anything you give her, whether it be spinach or beets or bananas or peaches or pears, plain whole wheat toast, whatever...she isn't picky, and I totally believe it is because I FED her these foods. I never push them on her...if she opens her mouth, I feed her, and I give her finger food...if she eats it, great, if not, oh well! Oh yes...and SHE has no teeth, either. I quit being so paranoid about her choking. My rule of thumb is, if I can mush it between my tongue and the top of my mouth, she can have it.
I would start now, if you can...do baby cereal for breakfast, and if you want, mix in a little baby food fruit. Do a little veggies for lunch, and a little for supper. Start giving something other than Kix...try very soft cooked carrots or green beans, cut up, or the toast (but don't use white, it turns mushy and is harder for them to break up and swallow.) Also, you could start giving some of the formula in a cup with meals instead of always in a bottle...the time is coming up to get rid of the bottles anyhow! :)
I hope this helped...honestly. I know everyone says all they need is formula or breastmilk for the first year (someone said a year and a half?!) but in my experience (and I know a WHOLE lot of babies, believe me) the ones who do only formula are tubby babies and turn into tubby toddlers. Like I said, mine is totally breastfed, but it's a good balance of food and milk and she is definitely healthy. And has a good relationship with food, where my oldest picks and eats like a bird.