POTENTIAL tenants can get a first-hand look at the inside of The Gateway at the twin towers' 9,000-sqaure-foot show suite in Tsim Sha Tsui. The suite is finished in the same materials as The Gateway and displays models of the detail of the building's exterior, location, grand entrance, the shopping floor atrium as well as typical floor layouts. It will highlight the hi-tech features that will be included in the complex: a fully diversified fibre-optic telecommunications system; emergency power back-up for tenants' computers; and a computerised building automation system that has direct digital control. Doreen Lee, director and general manager of marketing agent Harriman Leasing, said: ''Gateway will be the most intelligent office building in Tsim Sha Tsui, and its advanced systems will add a great deal of value to the operation of many office businesses.'' About 100,000 sq ft of office space has been leased already. Included among the tenants are Texas Instruments, Novi Footwear, Chan Wong Chung and Company, Caltex Langton and Sumikin Bassan. Ms Lee said a further 200,000 sq ft was under negotiation. Rents are from $35 per square foot to $45 per sq ft. The towers are being developed by Wharf Properties Limited. When finished, they will include more than 1.2 million sq ft of office space, a three-level retail podium of 120,000 sq ft that will have shops, restaurants and four mini-cinemas. The complex will be linked to Harbour City and its more than 500 retail shops, restaurants, cinemas and hotels. Floors five to 28 of each tower are linked, providing a twin floor plate of 37,000 sq ft. Floors 29 to 36 of each tower will not be connected and each will have a floor plate of 18,500 sq ft. The office space is being built in two stages: phase one, the retail podium to the 25th floor, is scheduled to be finished by April; and phase two, from the 26th floor to the top, should be completed by the middle of the year. The occupation permits for each phase are expected to be issued in April and July, respectively. The Gateway's location in Canton Road, together with the predicted shortfall of prime property throughout the territory expected between now and the end of 1995, made it an obvious target for new and expanding companies, Ms Lee said. The leasing agents for The Gateway are First Pacific Davies and Richard Ellis. The towers are being clad in granite and mullioness solar-reflective glass and curtain walling. Inside, office lobbies will be dressed in granite. There will be 24 high-speed passenger lifts, which will be divided into three zones in each tower.