There are a lot of review and comparison sites out there but I will always turn to Amazon.com for the most comprehensive reviews of products, definitely the most user friendly.
This website provides reviews for whole pig BBQ grills: http://www.amazingribs.com/BBQ_buyers_guide/smokers/pig_roasters.html After you decide which type of grill you want, you can click on that grill and it will take you to the company website where you can place an order.
You can find reviews for a gas bbq grill at www.bbqs.com. They provide expert advice and sell accessories for the modern barbecue. You can find everything you need and more.
I will advise you to go to www.bbqguys.com and search for their grill reviews. They have different reviews on the top ten grills and find whatever grill you need base on the reviews.
Gas BBQ grill reviews will help you discover what other people think about a particular grill model. You can save time and money by reading reviews. Look for reviews that have at least 25 reviews to get a clear picture about the grill. Some people have different expectations and you want the review to be a fair one. If you can find a online site that has hundreds of reviews, then the pros and cons will even out.
There are many websites that inform readers about thermos barbecue grills. Gas grill views have various reviews regarding thermal bbq grills. I say check them out.
www.bbq.about.com is a great website with a huge variety of experts who understand exactly what you're looking for. I definitely recommend it for anyone whose unsure about anything bbq grill related.
If you want the best bbq grill reviews, then ask your friends what they would suggest. They will probably give you an honest review about the product if they use it. You can also get information about electric grills at the store that you purchase the grill from. After you get the grill, you can then go online and look at user reviews for the product.
BBQ island grills can be found here http://www.bbqislandinc.com/. This website would be for brand specific grills. If you want an island grill then go to this website http://www.buybullbbq.com/islands.html . They have a wide selection of available BBQ island grills.
There are many places that sells BBQ grill in the internet. One of the best place that sell good BBQ grill is this website (http://www.weber.com/home).
I am sure you can order any BBQ grill parts, as long as you know what part you want, and you have serial number of the grill and also the part number. Make sure you know what brand you have, go to their website and order what you want.
The best place to try checking for replacing the grill grates on your grill would be the company who makes the grill. Usually they list parts on their website.
I would look at the website " bbqguys.com", I would think they would have a good idea. And yes, the home improvement store you can find these bbq grill islands at is home depot.