Heya Rajiv2
As far as forward passenger door airstairs for the SGA (Eric Cantu) DC-9 sorry to tell 'ya buddy, but there aren't any included with the aircraft. However, all is not lost. If you want an easy way to place objects such as airstairs, fuel/baggage/battery/maintenance trucks, or hundreds of other items into any FS 2004 airport scenery then go get the excellent Lago FS Enhancer here:
http://www.lagosim.com/default.asp?act=scheda&p=100049&lang=engThe basic program comes in a demo (try before you buy) evaluation package. This evaluation package allows you to only place 5 objects/vehicles/buildings/etc. per airport. If you buy a product key (like I did for 33 US Dollars or 25 Euro) then you can place unlimited items into your FS 2004 scenery quickly and easily. You can even animate and add sounds to these objects. It's really, really cool!
I use a stock 737 panel (with full interior views) for my SGA DC-9. I also use the stock 737 sound files. There are many good looking freeware DC-9 panels out there, however, some of them would require that I tweak them heavily to get them "Just Right". And I already had a perfect 737 panel available so I just used it. I may in the future go back and download a panel for my DC-9. I don't know.